# coding:utf-8
import keyword
print(keyword.kwlist)

class MyClass:
    i = 12345
    def f(self):
        return 'hello world'


def f1(self, x, y):
    pass

# 常量
PI = 3.141592653589793238462643383279502884197169399375105820974944592307816406286


str = 'Runoob'
print(str[0])  # 输出字符串
print(str[2:5])  # 输出字符串第三个到第五个之间的字符串